Title : Vibrational oct as a tool to study melanomas and other skin lesions using telemedicine
Abstract:
Vibrational Optical Coherence Tomography (VOCT) is a new technique to image and measure the stiffness (elastic modulus) of cells, dermal collagen, blood vessels, and fibrotic tissue in skin and skin lesions. The technique applies acoustic sinusoidal sound waves noninvasively at frequencies of between 50 and 300 Hz and uses the reflection of infrared light to measure the displacement of skin as a function of applied sound frequency. The maximum displacement at different sound frequencies defines an acoustic spectrum that characterize normal skin and skin lesions. Normal skin has resonant frequencies at 50 Hz (normal cells), 100 Hz (dermal collagen), and 150 Hz (blood vessels). Cancerous skin lesions have new resonant frequency peaks at 80 Hz (cancer associated fibroblasts), 130 Hz (new thin blood vessels) and 250-260Hz (fibrotic tissue). Differentiation between normal skin, actinic keratosis (AK), basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma can be made using the ratio of the 50 Hz, 80 Hz, 130 Hz and 250-260 Hz peak heights and machine learning techniques. Skin cancers are characterized by large 80 Hz, 130 Hz, and 250-260 Hz peaks not found in normal skin and AKs. Differences in melanomas with different amounts of pigment are determined based on the pixel intensity versus depth plots obtained from OCT images of lesion cross-sections. 3D reconstruction of lesion OCT images, loss modulus of skin and skin lesions, and 3D maps of component stiffness versus depth are additional measurements that will be presented. Images and VOCT acoustic spectral data can be obtained and analysed remotely allowing skin lesion identification over the internet. The only requirement is that an assistant focus the device on the area of skin to be analysed using the camera and OCT images. Once this is done the device will automatically run data collection and save it in the cloud in a protected site. Once the data is collected it can be reviewed as simply as a color-coded image or analysed using machine learning techniques.
Audience Take Away Notes:
- The morphology of OCT images of skin and skin lesions and their interpretation
- The location of cellular, collagen, blood vessel, and fibrotic tissue peaks in vibrational spectra of tissue
- How to create 3D stiffness maps of lesions and to determine the location of lesion margins and depth
- Machine learning comparison of vibrational data and histopathological analysis of skin lesions
- The use of VOCT to differentiate between suspicious lesions and skin cancers and determine margins
- Use of VOCT to noninvasively analyze end point of cosmetic procedures
